Hotstick assembly for installing and removing devices from high voltage energized overhead power lines

ABSTRACT

A hotstick assembly for installing and removing an electric power line conductor device includes an electrically insulated hotstick. A lead screw driver is attached to an upper portion of the electrically insulated hotstick, the lead screw driver includes a vertical slot extending through a tubular pipe for engaging a horizontal pin on the device for clamping and unclamping jaws on the device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application claims priority to U.S. Provisional Application No.61/740,517 which was filed on Dec. 21, 2012.

BACKGROUND

The present disclosure relates to a hotstick assembly. Hotstickassemblies are used when a utility worker, such as a lineman, is workingon a live energized high-voltage electric power line conductor. Manydifferent tools are capable of being attached to an end of the hotstickto allow the utility worker to monitor an operating parameter of theelectric power line conductor, such as current or conductor temperature;and tighten nuts, open and close switches, or replace fuses.

Hotsticks have varying lengths and can even be telescoping so a singlepole can be used in several different applications. Hotsticks aregenerally made of fiberglass or another material that won't conductelectricity and provide a physical separation for the utility workerfrom the dangers of handling an energized power line conductor directly.

SUMMARY

A hotstick assembly for installing and removing an electric power lineconductor device includes an electrically insulated hotstick. A leadscrew driver is attached to an upper portion of the electricallyinsulated hotstick, the lead screw driver includes a vertical slotextending through a tubular pipe for engaging a horizontal pin on thedevice for clamping and unclamping jaws on the device.

A method of attaching a device to an electric power line conductorincludes connecting a lead screw driver on a hotstick assembly to adevice. The device is placed on the electric power line conductor withthe hotstick assembly. The hotstick assembly 9 is rotated in a firstdirection to fixably secure the device to the electric power lineconductor.

These and other features of the disclosed examples can be understoodfrom the following description and the accompanying drawings, which canbe briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a right side view of an example sensor transmitterreceiver unit (“STR unit”).

FIG. 2 illustrates a front view of the STR unit of FIG. 1.

FIG. 3 illustrates a cross-sectional view taken along line 3-3 of FIG.2.

FIG. 4 illustrates a cross-sectional view taken along line 3-3 of FIG. 2with an example hotstick.

FIG. 5 illustrates another cross-sectional view taken along line 3-3 ofFIG. 2 with the example hotstick.

FIG. 5 a illustrates an enlarged view of a keyhole slot.

FIG. 6 illustrates another cross-sectional view taken along line 3-3 ofFIG. 2 engaging a conductor.

FIG. 7 illustrates an example upper magnetic core subassembly.

FIG. 8 illustrates an expanded view of an example upper magnetic coreand an example lower magnetic core surrounding the conductor and anexample power supply transformer.

FIG. 9 illustrates a schematic view of the line mounted power supply,electronics and transmitter-receiver of the STR unit.

FIG. 10 illustrates an expanded view of the lower magnetic core, examplelead screw assembly, and an example hotstick guide tube.

FIG. 11 illustrates the collapsed view of the lower magnetic core, thelead screw assembly, and the hotstick guide tube.

FIG. 12 illustrates a cross-sectional view taken along line 12-12 ofFIG. 2.

FIG. 13 illustrates a cross-sectional view taken along line 13-13 ofFIG. 1.

FIG. 14 illustrates an exploded view of example support blocks mountingthe upper magnetic core subassembly and example upper and lower jaws.

FIG. 15 illustrates an exploded view of an upper magnetic core mount andthe upper and lower jaws.

FIG. 16 illustrates a hotstick assembly.

FIG. 17 illustrates a top view of the hotstick assembly.

FIG. 18 illustrates a front view of a quick driver.

FIG. 19 illustrates a top view of the quick driver.

FIG. 20 illustrates a cross-sectional view of the quick driver takenalong line 20-20 of FIG. 19.

FIG. 21 illustrates a front view of the quick driver and a cutaway viewof the drill driver.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate an example sensor transmitter receiver unit(“STR unit”) 1 installed on a power line conductor C for measuring andmonitoring various parameters of the power line conductor C and itsenvironment. The STR unit 1 is formed from a one piece upper housing 2and a one piece lower housing 3. The lower housing 3 is accepted into abead 4 formed on a distal end of the upper housing 2. In this example,the bead 4 which is an integral part of the upper housing 2 is formed bymachining a portion of the upper housing 2 to form a groove on theinside of the bead 4. The lower housing 3 is secured to the bead 4 andthe upper housing 2 by a collar 5. The collar 5 attaches to a hotstickguide tube 13 (FIG. 3) that is secured to the upper housing 2 andextends through the lower housing 3.

In one example, the upper housing 2 and the lower housing 3 are made ofaluminum or other suitable electrically conductive material. Thematerial chosen should accommodate subassembly installation without theuse of external surface fasteners which could generate corona dischargesdue to high voltage being applied to the upper housing 2 and the lowerhousing 3. The upper housing 2 has the advantage of reducing the numberof mating surfaces and eliminating mismatches between multiple castparts which can generate corona discharges and audible noise due toslightly offset sharp edges of the mating surfaces of the adjacentcastings.

Referring to FIGS. 3 and 4, before the STR unit 1 is clamped onto theconductor C, a lower jaw 7 is moved to its fully lowered position spacedfrom upper jaws 6. This allows the conductor C to pass from position “A”of FIG. 3 through a throat T on the left side of the upper housing 2 andonto the upper jaws 6 in position “B” as shown in FIG. 5.

With the lower jaw 7 of the STR unit 1 in its fully lowered position, aspecially designed hotstick 10 is inserted into the bottom of the STRunit 1 and inside the hotstick guide tube 13. In this example, thehotstick 10 is made of an electrically insulated material such asfiberglass. The hotstick 10 includes a hotstick driver assembly 9 (FIG.4) attached to the hotstick 10 with a pin 36. The hotstick 10 providesthe required electrical insulation between the hands of the linemen andthe energized conductor C. A flexible stirrup assembly 11 (FIG. 4)contains a flexible braided conductor 12 which bends out of the way toallow the hotstick driver assembly 9 to enter a hole in the collar 5. Asmentioned earlier, the collar 5 secures the lower housing 3 to the bead4 on the upper housing 2. The collar 5 is fastened to the hotstick guidetube 13 using the set screw 5 a which is screwed into the collar 5 andinto a hole in the hotstick guide tube 13.

With the hotstick 10 and the hotstick driver assembly 9 fully engagedinside the hotstick guide tube 13, the STR unit 1 can be lifted by thelineman with the hotstick 10 onto the conductor C while maintaining theSTR unit 1 securely attached to the hotstick 10.

The upper housing 2 includes two jaw inserts 8, shown in FIGS. 5 and 14,located adjacent the throat T and the upper jaws 6. The two jaw inserts8 include inclined surfaces 8 a and the upper jaws 6 include inclinedsurfaces 6 a. The angle of incline of the inclined surfaces 8 a matchesthe angle of the incline of an inclined surface 2 a on the upper housing2.

The angle of the inclined surfaces 6 a is steeper than the angle of theinclined surfaces 8 a and the inclined surface 2 a to aid in installingthe STR Unit 1 on the conductor C. As the conductor C slides across theinclined surfaces 2 a and 8 a and reaches the steeper incline of theinclined surface 6 a, the STR unit 1 will bounce slightly upward andland in a circular notch 6 b of the upper jaws 6 (See FIG. 4). Thisallows a conductor temperature sensor to be mounted vertically and inthe middle inside the upper jaws 6 and initially extends slightly belowthe circular notch 6 b for the upper portion of the conductor C. The twodifferent inclined surfaces 6 a and 8 a of the jaw inserts 8 and upperjaws 6 prevent the conductor temperature sensor S, shown in FIGS. 3 and4, from becoming damaged since the conductor C firmly lands verticallyin the circular notch 6 b of the upper jaws 6 and pushes the conductortemperature sensor S up to the inside surface of the circular notch 6 b.

In FIG. 3, the lower jaw 7 is located in a pocket P between two legs ofa lower magnetic core 14. The lower jaw 7 is held in place with twospring pins 132 and 133 (FIG. 15) located in the lower jaw 7 that snapinto two holes 15 in a lower jaw holder 16 (FIGS. 10 and 11) which isattached to a bottom block 19 using two screws 20 (FIG. 3). The bottomblock 19 is located adjacent the base of the upper housing 2.

Two identical electrically conductive lower core covers 17 partiallysurround the two legs of the lower magnetic core 14. The lower corecovers 17 are attached to the bottom block 19 on each side of the lowerjaw holder 16 using screws 18 of FIG. 3 on the front right side and oneset of the screws 18 on the back left side (not shown). The front andback lower jaw holders 16 are both held in place by the four screws 20,two in the front and two in the back. The two legs of the lower magneticcore 14 are totally encased by the two lower core covers 17 and thefront and back lower jaw holders 16. Therefore, the lower magnetic core14 is not exposed to any moisture, such as from rain, snow, and ice thatcould enter through the throat T of the upper housing 2 (FIG. 3).

The bottom block 19 contains a conical hole 21 in the center whichprovides a very low friction bearing surface for the semi-circular topof a lead screw 22 (FIG. 3). The lead screw 22 is held in the conicalhole 21 with a retainer plate 23 which has a hole in the middle the sizeof the lead screw 22 diameter and is fastened to the bottom block 19.The lead screw 22 is threaded into the center of a threaded bushing 25.The threaded bushing 25 has a reduced diameter cylindrical lower portionwhich fits inside the hotstick guide tube 13 and a larger diametercylindrical top portion of the threaded bushing 25 is supported on theupper end of the hotstick guide tube 13. Both the threaded bushing 25and the hotstick guide tube 13 are attached to a hotstick guide support26 using two large through bolts 27 and nuts which are placed throughthe holes in a bottom support 28.

Referring to FIG. 2, the upper jaws 6 include two spaced apart jaws andthe lower jaw 7 includes a single jaw aligned between the two spacedapart upper jaws 6. When lower jaw 7 is clamped onto the conductor C,the conductor C is bent slightly upward as the lower jaw 7 extendsupward between the upper jaws 6 creating a bending moment in theconductor C. The bending moment in the conductor C prevents the STR unit1 from sliding down the conductor C, especially when the STR unit 1 ismounted at the point of attachment adjacent a utility pole or towerwhere the slope of the conductor C is at its maximum value. Preventingthe upper jaws 6 and the lower jaw 7 from sliding down the conductor Cat the point of attachment is necessary when the STR unit is being usedto measure sag of the power line conductor.

Referring to FIGS. 5 and 5 a, the bottom support 28 includes an upsidedown “U” shaped cross member and is fastened at each end to the upperhousing with two large threaded screws 29 on each side. The threadedbushing 25 has two small vertical holes 25 a drilled through thethreaded bushing 25 on each side of the threaded hole in the middle forthe lead screw 22. The vertical holes 25 a are countersunk on the topand provide drainage paths for fluid, such as rain water, that canaccumulate underneath the bottom block 19 and on top of the bottomsupport 28 (FIG. 5 a). The water then drains through the two verticalholes 25 a in the threaded bushing 25 and drops on the inside of thehotstick guide tube 13 and out the bottom of the STR unit 1. Therefore,water will not leak into the lower housing 3.

Referring to FIG. 6, the lead screw 22 has a small diameter hotstickguide 30 which is threaded on the inside and is screwed on the bottom ofthe lead screw 22. A pin 31 keeps the hotstick guide 30 from turning onthe lead screw 22. The hotstick guide 30 prevents the inside of ahotstick lead screw driver 33 from coming into contact with the threadson the lead screw 22 and damaging the internal bore of the lead screwdriver 33. It also guides the lead screw driver 33 onto the lead screw22. When the pin 31 engages the lead screw driver 33 the STR unit 1 isready for installation on the conductor C.

The hotstick driver assembly 9 includes the lead screw driver 33, ahotstick driver coupling 32, a rivet 34, a hotstick sleeve 35, the pin36, and the hotstick 10. The hotstick 10 of FIG. 4 rests on the roundedportion of the hotstick driver coupling 32 and the rounded inside bottomof the hotstick guide tube 13. This prevents the lead screw driver 33from applying pressure to the threaded bushing 25 upon installation ofthe STR unit 1 on the conductor C. The lead screw driver 33 and thehotstick driver coupling 32 are each fastened to the hotstick sleeve 35by the rivet 34 and the hotstick sleeve 35 is attached to the hotstick10 with the pin 36. A long narrow vertical slot in the lead screw driver33 allows the pin 31 of the lead screw 22 to be engaged with the leadscrew driver 33 and is free to slide up or down in the vertical slot 37as the lead screw is turned to tighten the lower jaw 7 on the conductorC or to loosen the lower jaw 7 from the conductor C to remove the STRunit 1.

The full length of the fiberglass portion of hotstick 10 including arubber end cap 402 shown in FIG. 16 depends on the operating voltage ofthe conductor C upon which the STR unit 1 is to be installed and thespecific work rules of different electric utilities whose lineman workon energized conductors C. The full length chosen provides a safeworking clearance between the hands of the linemen who may be wearingrubber gloves and holds the hotstick portion 10 during the installationof the STR unit 1 and removal from the energized line voltage potentialof the conductor C.

At the bottom of 10 is the rubber end cap 402 which fits over theoutside of the tubular fiberglass hotstick 10 which is normally filledinternally with an electrically insulating foam which prevents waterfrom condensing on the inside of the hotstick 10.

The keyhole horizontal slot 38 which is cut as a small arc of 45 degrees(see FIGS. 16 and 17) beginning at the center of the vertical slot 37 onthe front left side and ending on the back right side of the driver 33near the top. The horizontal slot 38 accommodates engagement of the pin31 of the STR unit 1 when the hotstick assembly 9 is manually turned bythe lineman in a clockwise direction. When this pin 31 is engaged withthe horizontal slot 38, the hotstick assembly 9 can no longer fall outthe bottom of the STR unit 1. Before the STR unit 1 is to be installedon a line conductor C, the hotstick assembly 9 is inserted into thehotstick guide tube 13 of FIG. 4 with the pin 31 in the long narrow slot37 near the bottom of 33. This pin 31 does not rest on the bottom of thelong narrow slot 37. The full weight of the STR unit 1 instead istransferred from the rounded inside bottom end of the hotstick guidetube 13 to the rounded outside end of the coupling 32 as shown in FIG. 4when the lineman lifts the STR unit onto the conductor C. Thisarrangement keeps the top end of the lead screw driver 33 fromcontacting the threaded bushing 25 of FIG. 5 when the STR unit 1 islifted onto the conductor C.

When the hotstick driver assembly 9 is engaged with the lead screw 22 asshown in FIG. 4, the STR unit 1 is raised to position “A” relative tothe height of the conductor C. The STR unit 1 is then moved toward theconductor C so that the conductor C passes through the throat T of theupper housing 2 and into position “B” as shown in FIG. 5. Once the STRunit 1 is fully supported by the conductor C in position “B”, thehotstick driver assembly 9 is turned clockwise by the installer with thehotstick 10 and allowed to drop down from its position in FIG. 4 to alower position as in FIG. 5. A horizontal keyhole slot 38 of the leadscrew driver 33 is now engaged with the pin 31 of the lead screw 22.With the pin 31 in the horizontal keyhole slot 38, the hotstick driverassembly 9 and the hotstick 10 are secured to the STR unit 1.

In this example, an opening and closing mechanism 39 of FIG. 6 extendsthe lower jaw 7 upward to secure the STR unit 1 on the conductor C.Additionally, the opening and closing mechanism 39 can also retract thelower jaw 7 to remove the STR unit 1 from the conductor C. The openingand closing mechanism 39 shown in FIG. 6 includes the lower magneticcore 14, the lower core covers 17, the lower jaw holders 16, the lowerjaw 7, spring pins 132 and 133, the bottom block 19, the retainer plate23, two fasteners 24, the lead screw 22, the hotstick guide 30, and thepin 31.

FIG. 6 illustrates the keyhole slot 38 on the lead screw driver 33engaged with the pin 31 on the lead screw 22. As the lead screw 22 isturned clockwise, the opening and closing mechanism 39 moves the lowermagnetic core 14 toward an upper magnetic core 40. The upper magneticcore 40 has two large compression springs 41 to bias the upper magneticcore 40 downward. The compression springs 41 provide pressure to holdboth the upper magnetic core 40 and the lower magnetic core 14 togetherto reduce the magnetic reluctance caused by air gaps 54 (FIG. 8) betweenthe upper magnetic core 40 and the lower magnetic core 14.

The hotstick driver assembly 9 can continue to be turned clockwise evenafter the lower magnetic core 14 begins to mate with the upper magneticcore 40 because the compression springs 41 compress at the top of theupper magnetic core 40. The clockwise motion of the hotstick driverassembly 9 can be achieved either manually or with a battery powereddrill or another rotating device, until the lower jaw 7 is tightenedonto the conductor C. After the STR unit 1 is mounted on the conductorC, the hotstick 10 is turned slightly to the left, or counterclockwise,and the pin 31 will become disengaged from the horizontal portion of thekeyhole slot 38. The hotstick 10 is then free to be removed when the pin31 aligns with the vertical slot 37.

To remove the STR unit 1 from the conductor C, the lineman inserts thehotstick assembly 9 into the hotstick guide tube 13 as shown in FIG. 4with the pin 31 placed in the assembly in the vertical slot 37 of thehotstick assembly 9. Once the hotstick assembly 9 is turned manuallycounterclockwise and the lower jaw 7 becomes loose from the conductor C,the hotstick is pushed up until the coupling 32 is resting against thebottom of the guide tube 13. The STR unit 1 is then ready to be liftedoff the conductor C.

FIGS. 7 and 8 illustrate the bottom of the compression springs 41 areheld in alignment in two cylindrical pockets 42 of two identicalhorizontal upper core blocks 43 which are each used to clamp the uppermagnetic core 40 to two identical magnetic horizontal lower core blocks44. The top of the compression springs 41 are held in place with twoprojections 49 extending downward on the inside of the upper housing 2of FIG. 8. The compression springs 41 are totally enclosed by the upperhousing 2 and are protected from the adverse weather which can causecorrosion. The air gaps 54 between the upper and lower magnetic cores 40and 14 are totally enclosed by the upper housing 2 which prevents theair gaps 54 from becoming corroded due to moisture from the environment.The horizontal upper core blocks 43 and the horizontal lower core blocks44 are clamped around the upper magnetic core 40 on each side using twothrough bolts 45 and two nuts 46 in the front and two through bolts 45and two nuts 46 located in the back of the upper horizontal core blocks43 and horizontal lower core blocks 44.

When the two large compression springs 41 push the upper core blocks 43down, the upper magnetic core 40 is prevented from falling out of a leftcore shoe 50 and a right core shoe 51, by a step 52 located at thebottom of the right core shoe 51 and a step 53 located at the bottom ofthe left core shoe 50.

When the lower magnetic core 14 mates with the upper magnetic core 40,the lead screw 22 can be turned further clockwise to move the two uppercore blocks 43 away from the steps 52 and 53 and further compress thecompression springs 41. The lead screw 22 can continue to be turnedclockwise and compress the compression springs 41 until the lower jaw 7and the upper jaws 6 are tight on the conductor C.

Electrical insulating spools 47 are inserted over each of the throughbolts 45 and electrical insulating washers 48 are inserted under thehead of each through bolt 45 and under each nut 46. The insulatingspools 47 and the insulating washers 48 on each of the through bolts 45prevent shorted electrically conductive paths around the upper magneticcore 40 which is comprised of the four through bolts 45, four nuts 46,the two electrically conductive upper core blocks 43 and the two lowercore blocks 44.

When the upper jaws 6 and the lower jaw 7 are firmly tightened on theconductor C, the compression springs 41 are compressed to their maximumdistance, and thus the maximum compressive force is also applied to thelower magnetic core 14 and the upper magnetic core 40. This decreasesthe size of the air gaps 54 between the lower magnetic core 14 and theupper magnetic core 40 and the magnetic reluctance between the lowermagnetic core 14 and the upper magnetic core 40. Depending on the sizeof the conductor C, varying amounts of torque can be applied to thehotstick driver assembly 9 to tighten the opening and closing mechanism39 on the conductor C.

The physical size and shape of the upper jaws 6 and the lower jaw 7 aredesigned such that approximately the same compressive force is appliedto the upper magnetic core 40 and the lower magnetic core 14. In oneexample, there are five different sets of upper and lower jaws 6 and 7that can fit different conductor sizes and types ranging from 0.162inches in diameter and up to 1.17 inches in diameter. The opening andclosing mechanism 39 allows the STR unit 1 to be installed on a widerange of conductor diameters without changing the upper jaws 6 and thelower jaws 7 while maintaining sufficient contact between the uppermagnetic core 40 and the lower magnetic core 14 to complete the magneticcircuit of the power supply transformer 55 of the STR unit 1 whichderives its power from the current flowing through the conductor C topower a power supply module 60 of FIG. 9. Because the STR unit 1 derivespower from the conductor C, batteries or solar cells are not required topower the STR unit 1. The STR unit 1 is powered at all times whencurrent is flowing in the conductor C, even at current levels as low as6.8 amperes and still process data and transmit data at 1 watt powerlevels because of the low threshold of the power supply module 60.

Maintaining a minimum magnetic reluctance insures that a power supplytransformer 55 (FIGS. 8 and 9) will provide the needed secondary voltageV₂ and secondary current I₂ to operate the power supply transformer 55,sensor electronics module 63, and transmitter/receiver 64. The powersupply transformer 55 includes the upper magnetic core 40, the lowermagnetic core 14, and a coil winding 56. The upper magnetic core and thelower magnetic core form a window W for accepting the conductor C.

The number of secondary turns N₂ of wire on the coil winding 56 areoptimized to produce the required secondary voltage V₂ and secondarycurrent I₂ with a minimum of current I₁ in the conductor C. As seen inFIG. 8, the coil winding 56 is held in place by two coil bobbins 57which are supported laterally by the two upper core blocks 43 and thetwo lower core blocks 44. Secondary leads 58 a and 59 a of coil windings58 and 59, respectively, are connected to the power supply module 60which maintains the same level of secondary voltage across leads 61 and62 for the sensor electronics module 63 and the transmitter/receiver 64even though the primary current may range from 34 amperes up to 1000amperes. Lower primary currents of 6.8 amperes are achievable with thelow threshold current power supply module 60. The power supply module 60contains an energy storage device 256 (FIG. 13) which can power thetransmitter/receiver 64 when the conductor C current ceases to flow. Atransmitting and receiving antenna 81 for the on-boardtransmitter/receiver 64 is mounted on the upper housing 2 (FIG. 12).

Locating the coil winding 56, 58, and 59 on the upper magnetic core 40allows the heat from the coil winding 56, 58, and 59 to escape through avent 65 (FIG. 1) in the upper housing 2. When the conductor sensor Slocated within the STR unit 1 measures the temperature of the conductorC, it is important that the heat from the coil windings 56, 58, and 59does not affect the temperature of the conductor C or the conductortemperature sensor S, which is in electrical communication with thesensor electronics module 63. As shown in FIG. 6, a thermally insulatingbarrier 66 located below the coil windings 56, 58, and 59, allows for amore accurate temperature reading of the conductor temperature byblocking heat from the coil windings 56, 58, and 59.

FIGS. 10-12 and 13 illustrate the lower magnetic core 14 with the lowercore covers 17, the lead screw 22, the hotstick guide tube 13, and otherrelated parts in both exploded and collapsed views. The hotstick guidetube 13 is anchored at the top with the through bolts 27 that extendthrough the bottom support 28 and the hotstick guide support 26. (SeeFIG. 5 a). As seen in FIG. 10, a round cylindrical milled slot 67 islocated along opposing sides of the top of the hotstick guide tube 13 toaccept the through bolts 27 that support the hotstick guide tube 13.

A central hole 70 extends through a base plate support 68 and a baseplate 69 for accepting a bottom portion of the hotstick guide tube 13.The base plate support 68 and the base plate 69 are connected to eachother with four identical threaded screws 71. The hotstick guide tube 13is attached to the base plate support 68 and the base plate 69 with setscrews 72 and 73. Left and right side panels 76 of FIG. 12 are attachedto the base plate support 68 and the bottom support 28 for the lowercore 14 with the use of two identical screws 74 extending through thebottom support 28 and the side panel 76 and at the bottom with twoidentical screws 75 extending through the side panel 76 and the baseplate support 68.

The threaded bushing 25 rests on top of the hotstick guide tube 13 andis prevented from turning relative to the hotstick guide tube 13 using aset screw 77. The left and right side panels 76 not only provide addedstrength, but also provide the physical space to mount the power supplymodule 60, the transmitter/receiver 64, the sensor electronics 63, andsupport left and right lower core guides 78 and 79.

The left lower core guide 78 and a right lower core guide 79 are “U”shaped and guide the opening and closing mechanism 39 such that thelower magnetic core 14 is aligned with the upper magnetic core 40. Eachof the left and right lower core guides 78 and 79 are attached to theleft and right side panels 76 with four threaded screws 80. The lowerhousing 3 is placed over the hotstick guide tube 13 at the bottom andfitted up to the base plate 69 and held in place with the collar 5. Thismeans that once the collar 5 is removed, the lower housing 3 can beremoved thus allowing access to the power supply module 60, sensorelectronics module 63, and the transmitter/receiver 64 of FIG. 9 mountedinside and on the left and right side panels 76 for easy maintenance andrepair.

FIGS. 7 and 12-15 illustrate an upper magnetic core subassembly 40 amounted to the upper housing 2. The left and right core shoes 50 and 51support the upper magnetic core 40 such that the upper magnetic core 40can move freely up and down inside the left and right shoes 50 and 51.The left and right core shoes 50 and 51 are attached to the upperhousing 2 using four support blocks 86 and 87 of FIG. 14, right and leftupper core guides 90 and 93, and four vertical through bolts 94, 95, 96,and 97.

The upper magnetic core subassembly 40 a can be inserted through thethroat T and fastened to the inside of the upper housing 2. A topportion of the upper housing 2 is “C” shaped which provides a surface onthe inside for mounting a current sensing device 156 for measuring thepower line frequency current (60 Hz or 50 Hz) and a loop coil 157 formeasuring lightning stroke current (FIGS. 13 and 16).

The right core shoe 51 has two identical threaded holes 82 and 83 on thefront and back for a total of four, and left core shoe 50 has twoidentical threaded holes 84 and 85 on the front and back for a total offour as shown in FIGS. 7 and 14. As shown in FIG. 14, two identicalsupport blocks 86 on the right side are placed on the front and back ofthe right core shoe 51 and two identical support blocks 87 are placed onthe front and back of the left core shoe 50.

To align the two right side support blocks 86 with the two sets ofthreaded holes 82 and 83 on the right side of the right core shoe 51,threaded screws 88 and 89 are first inserted into the upper and lowerholes in the right side upper core guide 90 and then through the twoholes in the right support block 86 and screwed into the accommodatingthreaded holes 82 and 83 of the right core shoe 51. The two left sidesupport blocks 87 are held in alignment with the left core shoe 50 byfirst inserting two threaded screws 91 and 92 through the other end ofthe right side upper core guide 90 and then through the holes in theleft side support block 87 and screwed into the threaded holes 84 and 85of the left core shoe 50. The same process is repeated on the back sideby connecting support blocks 86 and 87 to the left upper core guide 93with the backside of the right core shoe 51 and the back side of theleft core shoe 50.

The purpose of the upper core guides 90 and 93 is to insure the two longvertical through bolts 94 and 95 placed through the vertical holes inthe two right side support blocks 86 and two long vertical through bolts96 and 97 placed through the vertical holes in the two left side supportblocks 87 line up with the four threaded holes in four threaded inserts98, 99, 100, and 101, which are embedded in the casting of the upperhousing 2. As seen in FIG. 14, the two right side support blocks 86 areprevented from falling down by inserting the back of a right side upperjaw holder 102 and the back of the left side upper jaw holder 103 overthe vertical through bolts 94 and 95 and threading nuts 104 and 105 ontothe two vertical through bolts 94 and 95 and tightening them down,respectively. The two left side support blocks 87 are held in place byinserting the vertical through bolts 96 and 97 through the front hole inthe right side upper jaw holder 102 and the front hole in the left sideupper jaw holder 103 and threading two nuts 106 and 107 on the verticalthrough bolts 96 and 97 and tightening them down, respectively.

In reference to FIGS. 14 and 15, four threaded through standoffs 108,109, 110, and 111 are screwed onto the four vertical through bolts 94,95, 96, and 97, respectively. The thermal barrier 66 is placed over thefour bottom holes of the standoffs 108, 109, 110, and 111 and screwed tothe standoffs 110 and 111 on the front left side with two flat headscrews 112 as shown in FIG. 15.

FIGS. 2 and 15 illustrate casting fillers 113 and 114 located on theback left and back right sides of the STR unit 1 and secured with roundhead screws 115 which are first inserted through holes in the castingfillers 113 and 114 and then through the two back holes on the right andleft side of the thermal barrier 66 and into the standoffs 108 and 109,respectively.

After the upper magnetic core subassembly 40 a is mounted, the left andright lower core guides 78 and 79 including the opening and closingmechanism subassembly 39 and the left and right side panels 76 areinserted through the bottom of the upper housing 2 (See FIG. 12). Fourscrews 29 are inserted through the two holes on the left and the twoholes on the right of the bottom support 28 and screwed into thethreaded holes of the upper housing 2. It should be noted that duringthe insertion process, the right lower core guide 79, shown in FIG. 12,slides around the outside surface of the right core shoe 51 andunderneath a tab 116 at the top as a weldment on the right upper side ofthe right core shoe 51.

As shown in FIG. 12, the tab 116 insures that the right lower core guide79 fits precisely around the outside of the right core shoe 51 toprovide a near perfect alignment of the lower magnetic core 14 with theupper magnetic core 40. The precise alignment between the upper magneticcore 40 and the lower magnetic core 14 reduces magnetic reluctance bydecreasing the air gaps 54. This results in a decrease in the thresholdcurrent for the operation of the power supply module 60.

Referring to FIGS. 14 and 15, the right side upper jaw holder 102 andthe left side upper jaw holder 103 support the two upper jaws 6 and thejaw inserts 8. The long vertical through bolts 96 and 97 which arescrewed into the threaded inserts 100 and 101 at the top and on theinside of the upper housing 2 fit through top holes 117 and 118 on theback and front of the right side upper jaw holder 102 on the right side.Also, flush mount screws 119 and 120 are inserted on the back andthrough corresponding holes in the right side upper jaw holder 102 andare screwed into the upper housing. The flush mount screws 119 and 120are installed before the upper jaws 6 and inserts 8 are mounted to theright side upper jaw holder 102. The same arrangement for mounting theleft side upper jaw holder 103 is followed using screws 121 and 122.

Right and left upper jaw keepers 123 and 124 prevent the upper jaws 6from dropping down on the inside, because spring pins 126 and 127 arelocated on the outside and when depressed snap into the holes 128 and129 of the right side upper jaw holder 102. The same procedure isfollowed with the left upper jaw keeper 124.

The jaw inserts 8 on the right and left sides of the STR unit 1 and infront of the upper jaws 6 are held in place by inserting threaded bolts130 and 131 into each insert 8 and through the right and left keepers123 and 124 and screwing into the upper jaw holders 102 and 103. Thespring pins 132 and 133 are included in the lower jaw 7 which whendepressed snap into the two holes 15 in the lower jaw holder 16.

The transmitting and receiving antenna 81 for the on-board transmitterand receiver 64 shown in FIG. 9 is mounted on the housing 2. The antenna81 is displayed in FIGS. 1 and 2 and is installed on the top left sidein FIG. 1. The solar sensor assembly 134 is located at the top of thishousing and on its vertical centerline (FIG. 13). The small hole 140located directly to the right of the conductor C allows access andadjustment of the electric power line sag sensor 140 (FIG. 1).

The hotstick assembly 9 is used to install the STR unit 1 on theconductor C, tighten the lower jaw 7 onto the conductor C and loosen thelower jaw 7 from the conductor C so the STR unit 1 can be removed. Thereis a benefit in reducing the time and the manual labor normallyencountered in tightening the lower jaw 7 on and loosening the lower jaw7 from the conductor C during the installation and removal processes.Also, there is a benefit of insuring the lower jaw 7 is clamped onto theconductor C with the required torque needed for all installationsincluding different conductor types (i.e. copper, and aluminum)stranding, and conductor diameters. Larger diameter conductors C requirehigher torques to be applied by the lineman using the hotstick assembly9. These two benefits can be achieved by using a quick driver 403 asshown in FIGS. 18-21.

A front view of the hotstick quick driver 403 is shown in FIG. 18. Thehotstick quick driver 403 replaces the end cap 402 of FIG. 16. Thehotstick quick driver includes a sleeve 404 which is partially slid overthe bottom end of the fiberglass tubular hotstick 10 until it mates withthe top surface of a disc 405 shown in FIG. 20. The disc 405 is held inplace with the two flat head screws 413 and 414 as indicated in the topview of FIG. 19. The flat head screws 413 and 414 are flush with thesurface of the sleeve 404 to prevent snagging the rubber gloves or thehands of the lineman when the quick driver 403 is rotated. The sleeve404 is attached to the fiberglass hotstick 10 with a round head rivet406 which fits through the top hole in the sleeve on one side, passesthrough the fiberglass tube 10 and sleeve 404 on the other side and ispeened on the opposite side to provide a rigid connection of thefiberglass hotstick 10 to the sleeve 404 as indicated in the top view ofFIG. 19.

The disc 405 has a circular hole 407 in the center through which a quickdisconnect 408 fits into the hole 407 and is held in place with a dogpoint set screw 409 of FIG. 20. There is a small hole 410 drilledthrough the wall of the circular portion at the top of the quickdisconnect 408 through which the end of the dog point of the set screw409 fits therein to prevent rotation of the quick disconnect 408 withrespect to the disc 405.

At the bottom of the quick disconnect 408 is a semi-circular groove 411shown in FIG. 20 which fits into the chuck of any conventional quickrelease drill chuck 415 of a drill driver 418 of which only the chuckand top end of the drill driver 418 is given in FIG. 21. To install thedrill driver 418 on the quick disconnect 408 the lineman pulls down anoutside knurled ring 416 on the chuck 415 and pushes the drill driver418 up onto the hex shaped disconnect 408 until fingers 419 of the chuck415 seat into the semi-circular groove 411 and then releases the outsideknurled ring 416 which springs up and causes the fingers 419 topermanently seat in the semi-circular groove 411. The fingers 419prevent the drill driver 418 from falling out the bottom of the quickdriver 403, and the male hex shaped disconnect 408 can be rotated by thefemale hex shaped pocket of the chuck. A tapered circular area 420 atthe base of the disc 405 matches the taper of the top of all knowncommercially available quick release drill chucks. Half circle cut outs412 on each side and at the bottom of the sleeve 404 allows the thumband index fingers of the lineman to reach in and pull down on theoutside knurled ring 416 to release the chuck 415 from the hex shapeddisconnect 408 and remove the drill driver 418 from the quick driver403.

With the drill chuck 415 attached to the quick disconnect 408 and thequick driver assembly 403 attached at the bottom of the hotstickassembly 9 of FIG. 16, the lineman with a forward and reverse directionbattery powered drill driver 418 can tighten the lead screw 22 which inturn clamps the lower jaw 7 onto the conductor C, or loosen the leadscrew 22 and unclamp the lower jaw 7 from the conductor C. During thetightening or loosening process, the lineman has one hand near the baseof the fiberglass hotstick 10 and the other hand on the trigger of thedrill driver 418. The quick driver 403 added to the assembly 9 is asafer process than when the lineman manually tightens and loosens thelead screw 22 because there is more safe working clearance between thelineman's hands and the high voltage conductor C, than when thelineman's hands are positioned one above another and thus higher on thehotstick 10 with the manual approach.

The reversible drill driver 418 may be dc powered with a battery or thedrill may have the ac option and be ac powered by clipping the two leadsof its power cord to the 120 volts if available on the secondary of theelectric utility pole. The one clip of the power cord would be attachedto neutral and the other clip is attached to either a L₁ or L₂ wire ofthe secondary.

The drill driver 418, whether dc powered with a battery, or ac poweredfrom the secondary wires on the electric utility pole may have anadjustable clutch torque control whereby different torque settings areavailable by turning the outside rotatable ring 417 behind the chuck ofthe drill driver to the torque required for that conductor type,stranding, and diameter. There are 18 different torque settings shown onthe outside rotatable ring 417 of FIG. 21. By selecting the correcttorque setting this ensures the STR unit 1 is clamped onto the conductorC tight enough to prevent rotation of the STR unit 1 on the conductor C,but not be over-tightened to deform the stranding wires on the surfaceof the conductor C.

The preceding description is exemplary rather than limiting in nature.Variations and modifications to the disclosed examples may becomeapparent to those skilled in the art that do not necessarily depart fromthe essence of this disclosure. The scope of legal protection given tothis disclosure can only be determined by studying the following claims.

What is claimed is:
 1. A hotstick assembly for installing and removingan electric power line conductor device comprising: an electricallyinsulated hotstick; a lead screw driver attached to an upper portion ofthe electrically insulated hotstick, the lead screw driver including avertical slot extending through a tubular pipe for engaging a horizontalpin on a device for clamping and unclamping jaws on the device; and aquick driver located adjacent a bottom portion of the electricallyinsulated hotstick, the quick driver includes a quick disconnectconfigured to engage a driver on a power driver drill, wherein the quickdriver includes a tubular sleeve, a disc mounted inside the sleeve andthe quick disconnect is located in the center of the disc and mounted tothe disc.
 2. The assembly of claim 1 including a horizontal slot locatedadjacent an upper portion of the vertical slot for engaging thehorizontal pin on the device.
 3. The assembly of claim 2 wherein thehorizontal slot is arc shaped for preventing the hot stick assembly fromseparating from the device.
 4. The assembly of claim 2 wherein thehorizontal slot extends 45 degree relative to the vertical slot.
 5. Theassembly of claim 1 wherein the electrically insulated hotstick includesa fiberglass material.
 6. The assembly of claim 1 wherein a portion ofthe interior of the electrically insulated hotstick includes foam. 7.The assembly of claim 1 wherein the disc is tapered at the bottom forallowing for the insertion of a quick release chuck for fastening to thequick disconnect.
 8. The assembly of claim 7 wherein the quickdisconnect includes a hex shaped cross-section band a groove for matingwith a quick release chuck mechanism of a driver drill to prevent thedrill driver from falling off the quick disconnect.
 9. The assembly ofclaim 1 wherein the sleeve includes cutouts adjacent the bottom forallowing access to the quick release chuck to be pulled down forinstallation and removal of said chuck from quick disconnect.